Electronic wireless devices including mobile telephones, tablets, set-top boxes and gateway devices contain an increasing number of electronic components in an increasingly reduced space. They include, in particular, a high number of wireless features that require the integration of many antennas. The resulting density of circuits and components in a confined space is a real problem for the positioning and integration of the antennas on the main circuit board of such wireless devices because of the various constraints to cope with: lack of space, radio interferences to avoid, isolation between antennas to achieve etc.
FIG. 1 shows an example of a configuration of electronic components in a set-top box 11 including an antenna for transmission and reception of radio frequency waves. The optimum place for positioning an antenna is at the front of the wireless device. i.e. facing toward the user. However, the front area of the printed circuit board is already occupied by various components such as:                a first group a LEDS (LED#1), for indicating the status of some features of the device, activity and connectivity: Power, Wi-Fi, recording etc.        a second group of LEDs (LED#2) for illuminating the front panel logo.        a high bit rate USB3 connector        an infra-red (IR) sensor for remote control        other electro-mechanical control components such as push-buttons (PB).        
When these components are placed on the front edge of the PCB, the remaining space for positioning of antennas is limited.
In area A1, there is available space where would be possible to print an antenna; A second area A2 is also available, however because of the proximity of the USB3 connector, which can behave as a noisy interface, creating for instance electromagnetic interferences in the Wi-Fi 2.4 GHz band, this area therefore should be avoided. Area A3 is available for placing a second antenna. The problem here is the presence of the LEDs that are placed partially in front of the antenna. While the LEDs itself are not the real problem, since these components are quite “transparent” to radio-waves and barely impair the antenna behavior, the biasing lines for these components can degrade the sensitivity of antenna performance.
The present invention has been devised with the foregoing in mind.